A composite sintered body cutting tool is made of a composite sintered body comprising a TiCN-based cermet layer; and a WC-based cemented carbide layer. The angle between the rake face and the flank face of the cutting tool is 90°. The rake face including a cutting edge of the cutting tool is constituted from the WC-based cemented carbide layer, in which 4 to 17 mass % of an iron group metal component and 75 mass % or more of W are included; and a major hard phase component is WC. The thickness of the WC-based cemented carbide layer is 0.05 to 0.3 times the thickness of the composite sintered body. The TiCN-based cermet layer is constituted from a single layer of a TiCN-based cermet layer, including at least, 4 to 25 mass % of an iron group metal component, less than 15 mass % of W, 2 to 15 mass % of Mo, 2 to 10 mass % of Nb and 0.2 to 2 mass % of Cr in a case where contents of the constituting components of the cermet layer are expressed as contents of metal components, and satisfy the Co content relative to the total content of Co and Ni of 0.5 to 0.8 with respect to Co and Ni of the iron group metal component in a mass ratio. When the height profile from the upper end to the lower end of the flank face is measured in the plane, which passes the center of the rake face of the cutting tool and is perpendicular to both of the rake face and the flank face, as the line, which passes the ridge line where the rake face and the flank face intersect and perpendicular to the rake face, being the reference line, the maximum elevation difference value of the height profile is in a ratio of 0.01 or less with respect to the thickness of the composite sintered body from the front surface of the rake face to a rear surface.

A cermet and a cutting tool are provided which have high wear resistance and high fracture resistance at a cutting edge even in a mode of cutting where the cutting edge comes to have a high temperature. A cermet 1 includes a hard phase 2 including a carbonitride of one or more kinds of metals selected from Group 4, Group 5, and Group 6 metals of the periodic table including at least Ti and a binder phase 3 containing W and at least one kind of a metal selected from Co and Ni, wherein the binder phase 3 includes a first binder phase 4 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 0.8 or less and a second binder phase 5 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 1.2 or more.

A cermet and a cutting tool are provided which have high wear resistance and high fracture resistance at a cutting edge even in a mode of cutting where the cutting edge comes to have a high temperature. A cermet 1 includes a hard phase 2 including a carbonitride of one or more kinds of metals selected from Group 4, Group 5, and Group 6 metals of the periodic table including at least Ti and a binder phase 3 containing W and at least one kind of a metal selected from Co and Ni, wherein the binder phase 3 includes a first binder phase 4 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 0.8 or less and a second binder phase 5 in which a mass ratio of W to a total amount of Co and Ni (W/(Co+Ni)) is 1.2 or more.

Provided is a hard sintered body which exhibits excellent high temperature oxidation resistance and has a high hardness at a high temperature. In the hard sintered body, a binder phase is contained at from 8.8 to 34.4 mol % and the balance is composed of a hard phase and inevitable impurities. The binder phase contains iron aluminide containing FeAl as a main component and alumina that is dispersed in iron aluminide and has a particle size of 1 μm or less. The hard phase is composed of at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table, and solid solutions of these. This hard sintered body is obtained by mixing and pulverizing a binding particle powder containing an iron aluminide powder composed of at least one kind selected from FeAl.sub.2, Fe.sub.2Al.sub.5 and FeAl.sub.3 and a hard particle powder composed of at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table and then sintering a mixed powder thus obtained.

Provided is a hard sintered body which exhibits excellent high temperature oxidation resistance and has a high hardness at a high temperature. In the hard sintered body, a binder phase is contained at from 8.8 to 34.4 mol % and the balance is composed of a hard phase and inevitable impurities. The binder phase contains iron aluminide containing FeAl as a main component and alumina that is dispersed in iron aluminide and has a particle size of 1 μm or less. The hard phase is composed of at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table, and solid solutions of these. This hard sintered body is obtained by mixing and pulverizing a binding particle powder containing an iron aluminide powder composed of at least one kind selected from FeAl.sub.2, Fe.sub.2Al.sub.5 and FeAl.sub.3 and a hard particle powder composed of at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table and then sintering a mixed powder thus obtained.

In one aspect sintered cemented carbide articles are described herein which, in some embodiments, exhibit enhanced resistance to wear and thermal fatigue. Further, sintered cemented carbide articles described herein can tolerate variations in carbon content without formation of undesirable phases, including eta phase and/or free graphite (C-type porosity). Such tolerance can facilitate manufacturing and use of carbide grades where carbon content is not strictly controlled. A sintered cemented carbide body described herein comprises a hard particle phase including tungsten carbide and a metallic binder phase comprising at least one of cobalt, nickel and iron and one or more alloying additives, wherein the sintered cemented carbide has a magnetic saturation (MS) ranging from 0% to 73% and no eta phase.

In one aspect sintered cemented carbide articles are described herein which, in some embodiments, exhibit enhanced resistance to wear and thermal fatigue. Further, sintered cemented carbide articles described herein can tolerate variations in carbon content without formation of undesirable phases, including eta phase and/or free graphite (C-type porosity). Such tolerance can facilitate manufacturing and use of carbide grades where carbon content is not strictly controlled. A sintered cemented carbide body described herein comprises a hard particle phase including tungsten carbide and a metallic binder phase comprising at least one of cobalt, nickel and iron and one or more alloying additives, wherein the sintered cemented carbide has a magnetic saturation (MS) ranging from 0% to 73% and no eta phase.

Provided is a wear resistant, sintered body made of a binderless carbide, cermet or cemented carbide, e.g., WC, W2C and/or eta-phase, with a grain size less than 6.0 μm, and less than 6% binder phase (e.g., Co—Ni—Fe). At least some working surfaces of the sintered body are surface treated with a boron yielding method including applying a low viscosity liquid medium having boron or aluminum content and heating at 1200° C. to 1450° C. under a pressure less than atmospheric pressure or a hydrogen containing atmosphere to from a hardness gradient with an increased hardness of the treated working surfaces of at least 50 to 200 HV5 and favorable compressive stresses in a surface zone that gives a tougher working surfaces of the boronized sintered bodies.

An insert includes a base of a cermet including hard particles and a binder phase. The base includes first and second surfaces, a cutting edge on at least a part of a ridge line of the first and second surfaces, a third surface opposite to the first surface, and a through hole from the first surface to the third surface. An inner wall constituting the through hole includes a binder-phase-riched layer having a higher content of the binder phase than an inside of the base, at least in a center part. A thickness of the binder-phase-ricked layer in the center part is larger than a thickness of the binder-phase-ricked layer in an end part of the inner wall. A cutting tool includes a holder which has a pocket located at an end, the insert located in the pocket, and a clamp inserted in the through hole of the insert.

The disclosure relates to a method for preparing Ti(C,N)-based superhard metal composite materials, with Ti(C,N) powder and (W,Mo,Ta)(C,N) powder as main raw materials and Co powder as binding phase for preparation, thereby obtaining a material in which a microstructure is a double-core rim structure that has both a black core rim and a white core rim. The material has a complete and evenly distributed double-core rim structure. In the condition that the ensured hardness of the material is not reduced and even slightly increased, the toughness of the material is significantly improved, wherein the fracture toughness of the material is in the range of 11.3 to 12.5 MPa.Math.m.sup.1/2.